The built in BEC in the Avionic 20A ESC doesn't seem to be supplying any power to the receiver after i crashed my model. (My multimeter shows 0 volts)
I have to power the receiver externally to make it work

Is there a way to repair the ESC which would restore it to a normal condition 

Mirmoazam, if you are sure, there is no supply as 5 Volts, at terminal end, between red and black, or between red and brown, please just remove the heat shrink tube that wrapped the ESC with a sharp blade, by avoiding any touches to the Printed Circuit Board..now check the wires, as red and black, or brown for the continuity, means any internal breakage.. please check the pin connection at the tip of the termnal connector.. then carefully examine for any broken wire on PCB, if found any wire, especially, red and black, or red and brown, just resolder it, with a micro tipped soldering iron.. please use a fully shielded soldering iron, for any excess current leakages from iron.. or can plug out the plug of the iron, from wall socket.. then found OK, please check for any component lossage on PCB.. you can see two 7805 low drop regulators on one side of the PCB.. check for any prind breakages.. check short circuit protection device.. make sure the supply voltage from battery reaches to the input lead of the regulator..

Thanks Roopesh Sir, I found a Resistor which was not connected to the PCB, I restored the contact and the ESC is back to life again 

great work.. and have nice flights..

@mirmoazam
would you mind sharing with us how you fixed it?

Thank You Roopesh Sir

@ Dharmik, Yeah sure. But i haven't taken any photgraphs, i'll try explaining. There is a resistor just beside the Capacitor. One end of the resistor had come off the PCB. I got it soldered(One of my friend with good soldering skills). It hardly took a moment and my ESC was back to normal. I then covered the ESC with a Fibre Glass Tape as i don't have the heat shrink tube with a huge dia.